Articular cartilage is a unique tissue both in structure and function. Almost 70% of the dry weight of this tissue can be accounted for by collagen. This collagen differs from other mammalian collagens studied in that it is composed of 3 identical alpha-chains. It is extremely rich in OH-lysine residues and O-glycosidically bound carbohydrate. In the proposed experiments, we plan to: a) characterize chemically the collagen from normal and osteoarthritic cartilage of various ages. b) study the behavioral of these tissues in organ and cell culture, primarily in relationship to the synthesis of collagen. c) investigate the rates of turnover of this collagen "in vivo" and "in vitro" in various animal models. d) investigate the enzymatic susceptibility of these tissues. e) effect of enzymes on this collagen (protective effects of glycosaminoglycans?) f) role of the OH-lysine residues in glycosylation & crosslinking. g) association of the various types of collagen with osteophyte formation (i.e., Is the collagen in osteophytes of the bone type: (alpha 1) 2 alpha 2 or of the cartilage type: (alpha 1)3? In general, we are planning to systematically study the metabolism and chemistry of collagen in human cartilage in order to find out if there is an association of degenerative joint disease and the nature of the collagen present.